Heretofore, a disc medium such as an optical disc, magnetic disc, magneto-optical disc or the like has a spiral groove formed thereon for the purpose of tracking. It is already known to record address information by wobbling the groove adaptively to the address information.
For example, a CD-R (compact disc—Recordable) and MD (mini-disc) has formed thereon a spiral groove wobbled adaptively to an FM-modulated carrier signal (will be referred to as “FM modulation signal” hereunder) on the basis of address information. With the wobbles of the groove adaptively to the FM modulation signal, however, address information cannot be detected with a high accuracy and a given address cannot be accessed with a high accuracy when recording data to a disc medium and for reproducing data recorded in a disc medium. Therefore, for recording data to a disc medium, a very large link area (where no data is to be written) has to be provided before and after the data, which leads to a waste use of the recording area of the disc medium.